While Red Mud has been utilized in limited capacities as landfill material and the like, the prior art is not believed to contemplate or suggest the utilization of primarily red mud of an ideal particulate size for the absorption of industrial wastes, including liquid hydrocarbons, as well as non-hydrocarbon aqueous media, as contemplated in the present invention.
Pat. No. 4,270,875, entitled "Method of Creating Landfill from Red Mud", issued to Nippon Light Metal Co., Ltd. contemplates the utilization of compressed red mud "cakes" as a landfill medium for reclaiming land. Unlike the present invention, '875 contemplates the utilization of the red mud not in an absorbing capacity, but rather as a filler.
Pat. No. 5,456,553 issued 1995 teaches a "Soil or Ground Reinforcement Treatment Method" wherein there is disclosed a ground reinforcing composition, which may include red mud therein, for the purpose of reinforcing crushed stones, natural soil, or the like to enhance the strength and viscoelasticity thereof
Pat. No. 4,028,130 issued 1977 contemplates a "Disposal Method and use of Sewage Sludge" in which digested sewage sludge is transformed into a hardened composition that can then be used to form, as an example, a road base, using a mixture of 1-15% lime or the equivalent, 1-50% digested sewage sludge solids, and 20-90% fly ash, "or an equivalent amount of a fly ash substitute selected from the group consisting of siliceous incineration residue, "alum" water treatment plant waste, or "red mud" by-product of a bauxite reduction process, and water sufficient to provide a moisture content (based on weight % of dry solids) of 5-50%, the combination of said materials being cementitiously harden able under atmospHeric conditions", as set forth in claim Twenty.
First, the '130 reference defines "red mud" in only the broadest capacity, without an indication as to the components or makeup of the referenced material. The makeup and characteristics of red mud can vary considerably, depending upon the source and alumina extraction process used.
'130 clearly contemplates a composition that is "cementitiously hardenable" upon combining, unlike the present, applied for invention, which does not harden like a rock, (although technical properties would classify it as a silt with relatively low plasticity). Nonetheless, the absorbed mass provides better handling and more diverse use in a landfill or other capacity than pozzolonically hardened material, as taught in '130. Further, '130 does not disclose with specificity particulate sizes, and indicates a moisture content range believed to be in excess of what would be useful for the present invention.
Also, unlike '130, the present invention does not require water, a critical component in '130, to function in a useful capacity. Lastly, '130 contemplates a composition including sewage sludge, and does not consider other aqueous solutions, or as is the primary focus of the present invention, liquid hydrocarbon waste. Further, '130 is primarily directed to pozzolanic materials such as fly ash or the like, and only refers to "red mud" in a sort of alternative capacity, without revealing actual use or testing of a red mud composition. Indeed, based upon empirical evidence, the red mud composition of the present, applied for invention, would not pozzolonically react with water in the manner contemplated in '130. It is therefore suggested that, at least with the red mud of the present invention, the '130 red mud alternative could be argued as inoperative, or not provide the degree or type of containment as is contemplated in '130.
Besides the above patents, red mud has been used with the manufacture of building bricks, flame retardant materials, ceramics, and hydrocarbon catalysts.